Rotating machineries, such as motors, pumps, and compressors, are used in most industries, and damaged bearings are a cause of failure in about 70% of cases of motor failure, and is responsible for 30˜35% of failures in pumps and compressors.
The damaged bearings cost more damage than they are worth and the reason is that the damaged bearings inevitably inflict the delay of operations of the industry, which causes decreased productivity.
For these problems, the lubricant dispenser plays an important role in preventing damaged bearings and extending the lives of the bearings.
There was a way to inject directly the lubricant with a grease gun by the worker; however, there are many difficulties to be surmounted when pluralities of bearings need to be injected or they are inaccessible to the worker.
Consequently, various kinds of conventional apparatuses have been developed to inject the lubricant into the bearings and a typical example is shown in FIG. 1.
FIG. 1 is a schematic view illustrating a conventional lubricant dispenser of the prior art.
The conventional lubricant dispenser includes a cylindrical housing 1, a spring 2 installed inside the housing 1, and a piston 3 located in the bottom of the spring 2 inside the housing 1 so as to be forced by the pressure of the spring 2.
The lubricant pressurized by the piston 3 is stored below the piston 3.
At the center bottom of the housing 1, a cylindrical outlet tip 4 is formed to discharge the lubricant. The outlet tip 4 is fixed by insertion into a nipple formed in one side of the bearings in order to inject the lubricant. An inlet pipe 5 is formed to refill the lubricant at one side of the housing 1.
A ball valve (not shown) can be installed in the outlet tip 4 in order to adjust the discharged amount of the lubricant.
When the lubricant is injected into the housing 1 via the inlet pipe 5 with the above configuration, the spring 2 will become compressed while the lubricant is filled.
When the inlet pipe 5 is connected and fixed with the nipple of the bearings on the machine, the lubricant in the housing is continuously injected into the bearings through the nipple since the compressed spring 2 compresses the piston 3.
Since the piston continuously compresses the lubricant by the spring in the conventional automatic lubricant dispenser of the prior art, there can be an excessive oil-separation phenomenon in the lubricant, especially in the grease, as time goes by.
Oil-separation refers to a phenomenon in which the oil becomes separated from the grease and the solid thickener is all that is left.
When the oil-separation phenomenon occurs in the lubricant housing, the separated oil will be continuously drained away via the outlet tip located at the bottom due to gravity, only the solid thickener will be in the end left, and the grease cannot be normally discharged because the solid thickener is blocking the outlet tip.
Besides, the lubricant dispenser cannot be recycled because the lubricant cannot be refilled into the housing.
If the pressure of the spring is reduced in order to prevent the oil-separation phenomenon, the main objective of discharging the lubricant is rendered impossible because the lubricant cannot be smoothly discharged.
Because of these disadvantages, the conventional lubricant dispensers are not broadly used despite the simple structure, the inherent recycling, and the low cost.